No machine, however well designed and constructed, can last indefinitely. Whenever there are moving parts, there will be wear and degradation of machine components leading to reduced performance quality and ultimate breakdown. The period between installation of a new machine and its final scrapping due to lack of availability of cost-effective repair or obsolescence may be termed the "useful life" of the machine. Prolonging the useful life of machines and keeping the machines operating smoothly in healthy condition during their useful life periods have been areas of special interest to maintenance personnel in the manufacturing industry. This invention addresses maintenance issues by utilizing a methodology by which diagnostics, and hence smooth operation, of machines can be better accomplished. Though a wealth of literature is available in the area of machine tool diagnostics, ranging from repair manuals provided by original equipment manufacturers to specialized books by experienced consultants, the generality of the knowledge engineering approach described herein is believed to be new.
Sensor based analysis has become an important part of the maintenance management program for detecting machine condition changes in many manufacturing facilities. With the help of such an analysis, one can monitor a machine's condition, identify problems before major breakdowns occur, predict up-time, and plan for maintenance or repair work when it is most convenient in an effort to minimize production downtime. However, several years of expertise is usually needed before a machine maintenance person can fully utilize the power of sensor based analysis. A method of capturing and organizing that expertise in a knowledge engineering framework is described herein which enables inexperienced, or even new mechanics to effectively and efficiently diagnose machine problems.
While the present invention was conceived for the purpose of diagnosing machines making automobile parts, it is equally applicable to machines in the aerospace industry, ship building industry and other manufacturing businesses engaged in the production of medium and heavy duty products.